Method of sealing permeable earth surface or subsurface materials having alkaline conditions by induced precipitation of carbonates

The method of artificially creating an essentially hydraulically sealed stratum extending laterally over a preselected area beneath the earth's surface, said method comprising:

• (a) selecting a site at least coextensive with said preselected area having a subsurface stratum of initially fluid-permeable, alkaline materials having natural groundwaters therein;
• (b) extracting at least one sample of said groundwaters, and analyzing said sample to determine at least the carbonate and calcium content and the pH thereof;
• and
• (c) contacting said area with an aqueous, alkaline solution which combines with said groundwaters to produce precipitated calcite within said stratum to an extent rendering said alkaline materials substantially fluid-impervious.

The method of artificially creating an essentially liquid-impervious seal under alkaline conditions of a solid layer of material initially having cracks or voids which render said layer liquid pervious, said method comprising:

• (a) preparing an aqueous solution including dissolved carbon dioxide wherein the pH of said solution increases sufficiently upon degassing to become alkaline and cause precipitation of calcium carbonate from said solution;
• (b) contacting said solid layer with said solution under conditions permitting said carbon dioxide to esolve from said solution, whereby calcium carbonate precipitates from said solution;
• and
• (c) continuing said contact until the amount of precipitated calcium carbonate is sufficient to essentially fill said cracks or voids and render said layer substantially liquid impervious.